Cytotoxic metabolites from the mangrove endophytic fungus Aspergillus sp. GXNU QG1a

Abstract

A new benzoquinone, guxiumasperone A (1), and a new diisoprenyl-cyclohexene-type meroterpenoids, biscognienyne M (2), along with four known diisoprenyl-cyclohexene analogues was isolated from the mangrove endophytic fungus Aspergillus QG1a. Their structures were determined by extensive spectral analysis of 1D and 2D NMR, HR-ESI- MS, and X-ray crystallography. Compound 1 was deduced by a single-crystal X-ray diffraction analysis, and the absolute configuration of 2 was further unequivocally elucidated by comparing the experimental electronic circular dichroism (ECD) data with calculated ECD spectra. Compounds 1 and 2 showed significant cytotoxic activity against selected tumour cells. Particularly, compound 2 exhibited strong activity against A2780 cancer cells with an IC₅₀ value of 6.8 μM.

Graphical Abstract

Keywords:

• Aspergillus sp.
• mangrove endophytic fungus
• anthraquinone
• diisoprenyl-cyclohexene-type meroterpenoids
• anti-cancer function

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors (X.S. Huang) acknowledge the following agencies for funding this project: the National Natural Science Foundation of China (42066005); the Natural Science Foundation of Guangxi Province (2020JJA150036); Guangxi Science and Technology Base Special Talents (2019AC20095).